During the interview with Walt Mossberg at D5, Steve Jobs apparently let slip (according to the transcript from Gizmodo and Engadget), that even though the Apple iPhone won't start out of the gate with support for third-party applications, Apple is open to it and is working on making that possible later this year. Both transcripts imply that Jobs was concerned about security issues, which is what presumably was holding up the process. The lack of third-party support was one of the biggest complaints about the iPhone when it was first announced earlier this year, so if Apple actually makes this happen, it'll make a lot of people happy. (And one of them is me.) Now if only they'll work on 3G support as well.